• Overview

• Actions of PCP in the Brain
• Health Hazards
• Extent of Use

PCP (phencyclidine) was developed in the 1950s as an intravenous anesthetic. Use of PCP in humans was discontinued in 1965, because it was found that patients often became agitated, delusional, and irrational while recovering from its anesthetic effects. PCP is illegally manufactured in laboratories and is sold on the street by such names as "angel dust," "ozone," "wack," and "rocket fuel." "Killer joints"and "crystal supergrass" are names that refer to PCP combined with marijuana. The variety of street names for PCP reflects its bizarre and volatile effects.

Actions of PCP in the Brain

PCP prevents the actions normally caused when a neurotransmitter, called glutamate, attaches to its receptor in the brain. It also disrupts the actions of other neurotransmitters.

PCP is addicting; that is, its use often leads to psychological dependence, craving, and compulsive PCP-seeking behavior. It was first introduced as a street drug in the 1960s and quickly gained a reputation as a drug that could cause bad reactions and was not worth the risk. Many people, after using the drug once, will not knowingly use it again. Yet others use it consistently and regularly. Some persist in using PCP because of its addicting properties. Others cite feelings of strength, power, invulnerability and a numbing effect on the mind as reasons for their continued PCP use.

Many PCP users are brought to emergency rooms because of PCP's unpleasant psychological effects or because of overdoses. In a hospital or detention setting, they often become violent or suicidal, and are very dangerous to themselves and to others. They should be kept in a calm setting and should not be left alone.

At low to moderate doses, physiological effects of PCP include a slight increase in breathing rate and a more pronounced rise in blood pressure and pulse rate. Respiration becomes shallow, and flushing and profuse sweating occur. Generalized numbness of the extremities and muscular uncoordination also may occur. Psychological effects include distinct changes in body awareness, similar to those associated with alcohol intoxication. Use of PCP among adolescents may interfere with hormones related to normal growth and development as well as with the learning process.

At high doses of PCP, there is a drop in blood pressure, pulse rate, and respiration. This may be accompanied by nausea, vomiting, blurred vision, flicking up and down of the eyes, drooling, loss of balance, and dizziness. High doses of PCP can also cause seizures, coma, and death (though death more often results from accidental injury or suicide during PCP intoxication). Psychological effects at high doses include illusions and hallucinations. PCP can cause effects that mimic the full range of symptoms of schizophrenia, such as delusions, paranoia, disordered thinking, a sensation of distance from one's environment, and catatonia. Speech is often sparse and garbled.

Extent of Use

Monitoring the Future Study (MTF)*

NIDA's 1997 MTF shows that use of PCP by high school seniors has declined steadily since 1979, when 7.0 percent of seniors had used PCP in the year preceding the survey. In 1997, however, 2.3 percent of seniors used PCP at least once in the past year, up from a low of 1.2 percent in 1990. Past month use among seniors decreased from 1.3 percent in 1996 to 0.7 percent in 1997.

Percentage of 12th-graders who have used PCP:
Monitoring the Future Study